Quantum information processing and entanglement with Josephson charge qubits coupled through nanomechanical resonator

We present an experimental scheme to realize quantum phase gate between two Josephson charge qubits coupled through the nanomechanical resonator. In the scheme, two subsystems (qubits and resonator) in the time evolution operator are disentangled at the special time. Thus the scheme is insensitive to the state of resonator. We also demonstrate that the scheme can be directly used to create maximally entangled state of many charge qubits. (C) 2004 Elsevier B.V. All rights reserved.